Bulk material storage sites or dumps, in the art, are made up of rows of varying bulk material qualities. Since the pickup device, e.g., a wheel bucket loader picks up only the bulk material at the base of the dump, the material located above slides down without being checked. To avoid these disadvantages, it is already known in the art to provide a breakup device ahead of the pickup device. This delivers to the pickup device a section which extends uniformly across the dump cross-section not reached by the pickup device.
The breakup device may consist of a rake which is passed back and forth along the embankment of the dump as disclosed in German Pat., DT-AS 1 162 282. Due to this movement, the bulk material in the dump is loosened and slides down the dump embankment towards the pickup device. The pickup device usually consists of a bucket wheel located at the end of a boom. The disadvantage of the rakes also being located on the boom is, that they are relatively heavy, and therefore make necessary a similarly heavy counterweight at the other end of the boom.
Furthermore, it is already known in the art to use a rotating spiked roller extending across the embankment. Even the spiked roller, like the rake, can loosen the bulk material only by causing it to slide down. Hence both breakup devices can be used only for those bulk materials which are capable of sliding down. They are not suited for material stored in the open and exposed to the weather, such as coal, e.g., which tends to cake. In this case, no material mixture uniform throughout the dump cross-section can be removed.
Finally, it is also known in the art to connect a scraper chain ahead of the pickup device as disclosed in German Pat. DT-PS 1,243 103. This scraper chain, like the rake, has the disadvantage of being heavy and thus increases the expense of the overall structure.
During the removal of bulk material from the dump, the pickup device first travels in one direction along the dump. At the end of the dump, the direction of motion of the pickup device is reversed and again a section of the dump is removed. Therefore, one must require from the breakup device that it presents to the pickup device a section uniform across the dump cross-section for any direction of motion.
It is, therefore, an object of the present invention to design the breakup device for the above-mentioned arrangement in such a way that with small construction expenditure, a mixture uniform across the dump cross-section can be picked up even for bulk material which tends to cake. In addition, uniform bulk material must be possible even when the direction of motion of the pickup device is changed.
Another object of the present invention is to provide a breakup device of the foregoing character which is simple in design and has its parts readily accessible for maintenance and service.
A still further object of the present invention is to provide a breakup device, as described, which has a substantially long operating life.